Drag shovel



J. A. KUHSEL DRAG SHOVEL Feb. 27,1940.

Filed Dec. 17, 1337 5 Sheets-Sheet 1 Feb. 27, 1940.

.J A. KUHSEL DRAG SHOVEL Filed Dec. 17, 1957 5 Sheets-Sheet 2' Feb. 27, 1940.

J. A. KUHSEL DRAG SHOVEL Filed Dec. 17, 1957 Fig. 3

5 Sheets-Sheet 3 Feb. 27, 1940. J. A. .KUHS'EL DRAG SHOVEL Filed Dec. 17, 1957 5 Sheets-Sheet 4 tion of-the bucket Patented Feb. 27, 1940 PATENT OFFICE DRAG SHOVEL Joseph Albert Kuhsel, Hamburg- Altona, Germany Application December 17, 1931, Serial No. 180,437 In Germany March 13,- 1936 '1 Claims.

Drag shovels are known the bucket of which is moved from its transporting position into its digging position by means of a digging cable actuating the bucket outside its center of rotation, or in which the bucket is actuated by the lifting cable in such a way that it is tilted from its inoperative or transporting position into its operative or digging position. This means that in such drag shovels the bucket is always moved against the digger stop by means 'of the tightened cable, while when in transporting position it always can tilt by its tent only until the center of gravity lies below the center of rotation.

It is further known to provide in drag-shovels rigid, parallelogram-shaped guides by which the bucket is conducted in such a. way that independently of the different positions of the boom and of the digger-stick the bottom edge of the bucket is always moved on a parallel line in respect to itself. This arrangement excludes any possibility of changing at will the inclinafor dumping or transporting. A feature of the invention consists in the-fact that the lifting cable directly or indirectly actuates the bucket outside its center of rotation and, that the bucket by the action of such traction cable is raised in its transporting position beyond its center of gravity. Thus, a loss of excavated material during the slewing of the dipper-stick is substantially avoided and at the same time a position of the bucket is obtained permitting of its discharging its contents through an opening in the bottom.

It is a further object or the invention to provide drag shovel buckets which are moved from the transporting position into the digging position by a particular tilting cable. Such -a tilting cable is attached to the bucket in such a way that when the boom is raised and the diggerstick slewed, with the bucket in its transporting position the tilting cable will automatically maintain the bucket in the transporting position. This is accomplished by providing a uniformly tensioned cable irrespective of the boom andstick positions without necessitating during such movement any change in the length of such cable by operating the respective cable drum.

The invention is schematically shown in the attached drawings, in which:

own weight to such an ex-' end of lifting cable Fig. 1 is a" side view of a drag shovel in its several respective positions, viz:

(A) With lowered boom, bucket in digging posi-' tion, 5

(B) With raised boom and lowered dipper-stick,

bucket in its transporting position,

(0) With raised boom and lifted dipper-stick,

bucket in transporting position, the hatched lines indicating the digging po- 19 sition.

Fig. 2 is aside view similar to Fig. 1 of a drag shovel showing the same positions but showing a modified guiding of the tilting and lifting cables.

Fig. 3 is a side view of a bucket according to m Fig. 2, on enlarged scale.

Fig. 4 is a. plan view of Fig. 3.

Fig. 5 is a side view similar to Fig. 3 and shows afurther embodiment of the invention with a gearing inserted between lifting cable l2 bucket 9.

Fig. '7 is but showing another form of execution with variable gearing between cable and bucket.

Fig. 8.is a section view taken on line 1-1 of Fig. 'I.

In the said drawings 2 is a rotatable superstructure of a shovel with the supporting girder a being held in position by a strut A; at 5 the boom 6 is pivotally arranged and at the top 1 of boom 6 the dipper-stick 8 is pivotally arranged. At the front end of the dipper-Stick-B the bucket 9 is pivotally arranged to be rotated about the center of rotation I0, while at its rear end at H pulleys l8 are provided for the lifting cable l2 which passes over pulleys l3 and 49 respectively of girder 3. From there the cable I! passes to the lifting drum l5 which is provided with a brake H. From a second drum IS, the digging 40 cable 11 is guided to the digger-stick, sothat in a well known manner the boom ii and dipperstick 8 may be operated by both cables I! and 11. My device diflers from known devices in that one rear end H o! the dipper-stick or from pulley l3 of support 3 directly to a pulley l9 at the boom and fromthere to the curved surface 20 of the bucket, the said cable end being flxed to the bucket at II. This cable actuates the bucket'lrom 50 and 20 i2 is guided either from the 45 bucket, whereby to produce a tilting momentum .bucket and dipper-stick is produced when shift-' position 0, that is to say I pulley 21 is given a I the curved surface 2!! represented as a circle in' cable between drum 24 of the bucket around itscenter of rotation it in clockwise direction by which the bucket being in its transporting position is moved to such a point that the front wall of the bucketis held in a favourable position for both transporting the excavated material and for discharging thev latter through an opening in the bottom.

The tilting cable 22 is guided from the drum 24, provided with brake 22, either directly or over the pulley 25 to the pulley 28 at the structure of the drag shovel from whence it may pass over a' pulley 27 at the topof boom to the curved sur.'-, face 20 of the bucket where it may be fixed tothe bucket as at 28.

If, after completion of the digging motion the bucket is shifted from position A to position B by lifting the boom by means of lifting cable i2 the bucket is caused to take and maintain respectively, the most favourable position for transporting the material and for discharging it through the opening in the bottom. For this from the center of rotation I, to a curved surface purpose, a part'of tilting cable 22 is passed aroimd the curved surface 28. The length of cable required to accomplish this end is obtained by the fact that the centervof rotation of pulley 28 is arranged at such a distance and in such a direction from the center of rotation 6 of the boom that when the boom is vraised, the cable passes around said pulley, the distance between top I of the boom and the center of rotation of pulley 26 being simultaneously reduced to such an extent that, when the pulley 26 is suitably arranged, the difference between the shortening of distance 126 and the length of cable passing aroimd pulley 2G is identical to the length of cable passing around the curved surface 20 on its way irom A to B. In other wor the length of'the tilting not change in spite of the alteration of the angle between bucket and dipper-stick, so that once a favourable transporting the bucket is obtained it can be automatically galilxliltaizihed gligsiglt any actuation of the tilting e cable remaining rmly tightened at all times. mm

A further alteration of the angle between g from position B'to I when slewingforward the dipper-stick, so that during this operation a part of tilting cable 22 passes around the curved surface 22. If the diameter identical to thatv of this figure, the slewing of dipper-stick from B to C will result in a length of cable being uncoiled from said pulley identical to the length of cable coiled on curved surface 20. That is to say, the front wall of bucket 8 on its way from A to B is displaced parallel and thereby maintains its favourable position; ,When raising the boom and swinging forward the dipper-stick, no

matter whether suchop'erations take place one after another or simultaneously. the tilting drum 24 need not be actuated at all, the position of the front wall of the bucket being approximately maintained.

sition, indicated by hatched lines, by tightening the cable 22. It is then lowered for a new digging operation by loosening the lifting cable l2.

As during the downward movement of the bucket the latter does not change its position in relaand fixing point a does' tion to the dipper-stichthe til ting drum has to uncoil cable, an automatic compensation of the cable lengths as took place during the upward movement by cha ing the-angle between bucket and dipper-stick not being possible any more during this downward movement. It will be understood that during the downward movement any braking work necessary is partly done by the tilting drum brake 23, so that the braking heat produced when lowering the system is distributed on two brakes l4 and 23, thus favourably relieving lifting brake ll which has so far had to do all the braking work. In this arrangement the shape and the position of the curves or pulleys for the tilting cable canbe chosen simultaneously taking into account that a certain amount of braking work-is done by the brake ofthe tilting drum. I

A further embodiment of. the invention is shown in Fig. 2. In this instance the tilting cable 22 does not pass from pulley 26 over the top of the boom, but is guided over a pulley 2!, which is secured to the dipper stick at a certain distance II on the bucket, the said cable being fixed to the bucket at if. At the same time-Fig. 2 shows in which manner the one end of lifting cable l2 passes from the .pulleys I. to a curved surface 32 and is fixed to the bucket at 22. Whilethe efficiency of thus guiding the lifting cable is the same-as that of the arrangement shown in Fig; 1, it will be attained by particularly guiding the tilting cable, that is to say by the pulley 20 being outside the center of rotation I, and by forming the curved surface "for the tilting cable a to compensate for the variations of cable lengths.

.Also the length of the lever'arm of the tilting cable necessary fortilting the bucket into its digging podtion is increased, so that the forces merits of Figs. 1 and 2 without departing from the scope of the presentinvention, it'being possible to reduce thediameter of pulley 21 of Fig.

:compensating the diiferences of length of cable 22 resulting therefrom by giving curved surface 22 a shapeaimilar to curved surface 30 of .Fig. 2. Besides it will, of course, be possible to guide the lifting cable l2 inl 'lg. 1 tothebucketinthe same way as shown in" Fig. 2 without substantially changing the effective operation of such arrangement. Y 7 5 An invention also consists in combining the aforesaid new features; A bucket in its transporting position-on which aforceis exercised inclockwise direction by the lifting cable l2 being so passed to the bucket and which bucket is guided by the tilting cable as indicated above and is prevented from, yielding to said force, oifers the advantage'compared with the cable-governed buckets known sofar, that it does not alter its position during the slewing of the dipper-stick and during the rotation of the shovel respectively and does not begin to oscillate inthe longitudinal direction of the sheverundeithe action-oi is the accelerating and centrifugal forces respectively.

,Besides during the said movements the tilting cable is always kept tightened if from the beginning the curves 20 or 32 for the lifting cable are so dimensioned that the momentum in a clockwise direction produced by the lowering cable is superior to that one produced in the opposite direction by the center of gravity of the bucket.

The combination further brings about the advantage that the bucket when discharged through its bottom opening cannot react to the action of the displacement of the center of gravity caused by the discharging, the tilting cable, as already mentioned, not permitting a clockwise rotation of the bucket. This means that durin dumping the bucket is maintaining its position, so that its contents can be discharged at will at a certain point without any waste on the way.

Fig. 3 represents a bucket according to Fig. 2

on an enlarged scale, showing the manner in which the tilting cable 22 is passed over curve 30 and fixed at 3i. The lifting cable l2 passes over a curve 32, which in the prwent instance is represented as a semi-circle, and is fixed at 33. As already set forth, a momentum in clockwise direction is exercised on the bucket by the lifting cable l2 resulting in a position of the bucket favourable for its being discharged through the bottom opening. At the same time the tilting cable 22 by the shape of curve 30 and the means described above is guided in such a way that when moving the boom and the dipper-stick without operating the tilting drum 24, the bucket maintains its upright position brought about by cable i2.

Figs. 5 and 6 represent a further embodiment of theinvention with' a gearing inserted between lifting cable l2 and bucket 9. Such design is favourably used when the efficiency of the lifting cable i2 due to the arrangement of the system does not sufiice without ado for drawing the bucket into the desired position. In such cases where the curve 41 (Fig. 5) is to be so limited in size that the inlet opening of the bucket is not thereby affected. By using a gearing the center of rotation I can be chosen at will. It is possible to have it arranged if desired at a greater distance from the front wall of prejudicing the discharg g position of the bucket, as by a greater ratio of gearing the momentum at the bucket opposing the center of gravity of the bucket may be increased at will. The lifting cable l2 actuates a drum 31 in such a way that by means of the gearing 33, 39 a turning momentum of the desired degree in clockwise direction is exercised on the bucket.

In this instance the tilting cable 22 is shown passing over curve 11 and being fixed at 28, similarly as shown in Fig. 1. It will, of course, be possible to actuate the said cable at the opposite side of the drum 31, so that the turning momentum exercised on the bucket by the cable 22 for tilting the bucket may be increased according to the ratio of gearing.

The arrangement shown in Flgs. and 6 has the disadvantage that the momentum exercised on the bucket from cables l2 and 22 respectively by the constant ratio of gearing does not always have the. same relation to the momentum exer- 1 cised on the bucket bythe center of gravity, as

by moving the bucket about the center of rotation l0 out of the position shown in the drawings in a counter-clockwise direction. 'ihe center of cable being such as gravity on account of its varying horizontal distance from the center of rotation will at first support the action of cable 22, while when it has passed the dead center it will gradually and increasingly oppose such movement. This inconvenience can be overcome by so arranging the center of the toothed wheel 39 that it does not coincide with the center of rotation Ill, but is arranged independently of the bucket on the dipper-stick at a sufficient distance from the bucket proper. When inserting a guide between a point outside the center of said toothed wheel (crank) and a suitable point of the bucket, a variable relation between cable and bucket is at tained during the rotation of the bucket. Besides. such design will also be'advantageous on account of the fact that the force available in'the lifting, cable for moving the bucket into its transporting and discharging position will vary according to the distance of the bucket from the center of rotation of the boom. This means that the gearing ratio -1nay be permanently adjusted to the respective position of the bucket in such a way that the available force of the lifting cable will suflice in any case for attaining a favourable position of the bucket when transporting or dumping.

A further embodiment with variable gearing ratio between cables i2 and 22 and the bucket, as shown in Figs. 7 and 8, is obtained by a hookshaped guide-arm 4| actuating the bucket 9 at 40, the said guide-arm being pivotally mounted on shaft 42. The said shaft 42 is provided with gear pinion or pinions 43 engaging racks 44 secured to the dipper-stick. Furthermore, drums 45 and 46 for the lifting cable l2 and tilting cable 22 are reversibly mounted on shaft 62. If cable 22 is tightened, in order to tilt the bucket into the position marked by hatched lines, pinion 43 will run in the same direction on rack 44. At first the force exerted by the lever arm on the 7 center of rotation in for tilting the bucket will be small, while with progressive movement of shaft 42 in the direction of the cable traction, the force exerted by said lever arm increases in the same relation as the horizontal distance of the center of gravity from the center of rotation. Iii is increased.

What I claim is:

1. In an excavator including a dipper stick and a bucket pivotally attached thereto, means for actuating said stick and bucket through a digging operation to fill said bucket, means for transporting said filledbucket to a dumping point, said first means including a lifting cable, a drum therefor anchoring one end thereof, a pulley on the rear end of said stick, said cable passing over said pulley, gear means on said stick adjacent said bucket, meshing gear means on said bucket, means associated with said first gear means and engaging said cable whereby to rotate said first gear means and said meshing gear means and said bucket, the length of sag to raise said bucket above its center of gravity, and means for automatically maintaining said bucket in said raised position throughout the transportation thereof.

2. In an excavator including a dipper stick and a bucket pivotally attached thereto, means for actuating said stick and bucket through a digging-operation to fill said bucket, means for transporting said filled bucket to a dumping point, said first means including a lifting cable,-

a drum therefor anchoring one end thereof, a pulley on the rear end of said stick, said cable passing over said pulley and the free end thereof being attached to said bucket outside. its center of rotation, the length of said cable being such as to raise said bucket above its center of gravity, and means for automatically maintaining said bucket level throughout the transportation thereof, a curved surface on said bucket, said cable passing over said surface before being attached to said bucket.

3. In an'excavator, including a boom pivoted to said excavator, a dipper stick pivoted to said boom and a bottom-discharging bucket pivoted to said dipper stick; a tilting cable for holding said bucket in a digging position, means for actuating said stick and bucket through a digging operation to fill said bucket, means for raising said filled bucket to a combined transporting and discharging position with its front edge raised above the center of gravity of said bucket, means for actuating said boom and dipper stick to transport said filled bucket, and means associated with said tilting cable and saidbucket raising means for automatically maintaining said bucket in said transporting position irrespective of the position of said boom and dipper stick.

- 4. In an excavator, including a. boom, pivoted to said excavator. a dipper stick pivoted to said boom and a bottom-discharging bucket pivoted to said dipper stick; means for holding'said bucket in a dining Position, means for actuating said stick and bucket through a digging 0D- eration to fill said bucket, a lifting cable for raising said filled bucket to a combined transporting and discharging position with its front edge raised above the center of gravity of said bucket, a drum for said lifting cable anchoring one end thereof, a pulley on the rear end of said stick, said cable passing over said pulley and the free end of said cable being attached to said bucket outside its center of rotation, and means associated with said first named means for automatically maintaining said bucket in said transporting position irrespective of the position of said boom and stick.

5. In an excavator, including a boom pivoted to said excavator, a dipper stick pivoted to said boom, and bottom-discharging bucket pivoted-to said dipper stick; a tilting cable for holdlng'said bucket-in a digging p sition, means for actuating said stick and bucket through a dissing operation to fill said bucket, a lifting cable for raising said filled bucket to'a combined transporting and discharging position withits front edge raised above thecenter .of gravity of said bucket, the ends of said cables being attached 'with said tilting cable and said bucket raising transporting position maintaining means includ- 4 said filled bucket to a combined transporting and port said filled bucket, and means associated to said bucket on opposite sides of the centervv of rotation thereofto provide means for pivotin: said bucket in both directions through the longitudinal plane thereof, and means associated with said cables for automatically maintaining l saidbucket insaidtransporting pcsitionirre spective of the positions of said boom and stick. 6. In an excavator, including a boom pivoted to said'excavator, a dipper stick pivoted to said boom and a bottom-discharging bucket pivoted. to said dipper stick; a tilting cable for holding said bucket in a digging podtion, means for actuating said stick and bucket through a digging operation to fill said bucket, means for raising said filled bucket to a combined transporting and discharging position with its front edge raised above the center of gravity of said bucket, means for actuating said boom and dipper stick to transport said filled bucket, and means associated means for automatically maintaining said bucket in said transporting position irrespective of the position of said boom and dipper stick, said ing a pulley on said excavator adjacent to but outside the pivotal connection of said boom thereto, a second pulley in the region of the pivotal connection of said boom and stick, said tilting cable passing over bothof said pulleys before reaching said bucket.

7; In an excavator, including a boom pivoted to said excavator, a dipper stick-pivoted to said' boom and a bottom-discharging bucket pivoted to said dipper stick; a'tilting cable for holding said bucket in a digging position, means for actuating said stick and bucket through a digging operation to fill said bucket, means for'raising discharging position with its front edge raised above th e'center of gravity of said bucket, means for actuating said boom and dipper stick to transwith said tilting cable and said bucket raising means for automatically maintaining said bucket in said transporting position irrespective of the position of said boom and dipper stick, said transporting position maintaining means including a pulley on said excavator adjacent to but outside the pivotal connection of said boom thereto, a second pulley in the region of the pivotal connection of said boom and stick, said tilting cable passing over both of said pulleys before reaching said bucket, and cable actuated gearing operatively interposed between the free end of said cable and said bucket. I a

JOSEPH ALBERT KUHSEL. 

